1. Field of the Invention
An embodiment of this invention relates to a cogeneration apparatus, particularly to a cogeneration apparatus having a power generation unit equipped with a power generator and an internal combustion engine connected to the generator and to a hot water tank through a heat exchanger.
2. Description of the Related Art
In recent years, cogeneration apparatuses for household use have been developed each equipped with an engine-driven generator connected to an AC power supply line between a commercial power source and an electric load for supplying power to the load in interconnection with the commercial power source and also for supplying hot water or air heated by the engine exhaust to a thermal load, including one taught, for example, by Japanese Laid-Open Patent Application No. 2002-277053.
The cogeneration apparatus mentioned in the reference has a power generation unit equipped with an internal combustion engine connected to a power generator and to a hot water tank through a heat exchanger, a pump located at a flow channel connecting the hot water tank and the heat exchanger to supply heated tap water to the tank, and a controller for controlling operation of the pump in accordance with a temperature of the tap water retained in the tank.